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[en] In this study, gelatin–polyethylenimine blend nanofibers (GEL/PEI) were fabricated via electrospinning with different ratios (9:1, 6:1, 3:1) to integrate the properties of both the polymers for evaluating its biomedical application. From scanning electron microscopy, the average diameter of blend nanofibers (265 ± 0.074 nm to 340 ± 0.088 nm) was observed to be less than GEL nanofibers (403 ± 0.08 nm). The incorporation of PEI with gelatin resulted in improved thermal stability of nanofibers whereas the Young’s modulus was observed to be higher at 9:1 ratio when compared with other ratios. The in vitro studies showed that the GEL/PEI nanofibers with 9:1 ratio promoted better cell adhesion and viability. GEL/PEI nanofibers with 9:1 and 6:1 showed hemolysis within the permissible limits. From the results, it could be interpreted that GEL/PEI nanofibers with 9:1 ratio proved to be a better scaffold thereby making them a potential candidate for tissue engineering applications.
[en] Highlights: ► The damage development process of glass–epoxy laminated composite pinned-joints is experimentally investigated. ► The bearing strengths of pin-loaded glass–epoxy laminate composite with [0°/902°/0°]s and [0°/90°]2s stacking sequences are compared. ► The influences of geometric parameters on failure load and bearing strength of joint are investigated. ► Damage progression is examined by using scanning electron microscopy. -- Abstract: In this paper, the damage development process of glass–epoxy laminated composite pinned-joints is investigated. To determine the effects of joint geometry and stacking sequence on the bearing strength and damage mode, experimental studies were carried out. Two different geometrical parameters which are the edge distance-to-hole diameter ratio (E/D) and plate width-to hole diameter ratio (W/D) were considered. Hence, E/D and W/D ratios were selected from 1 to 5 and 2 to 5, respectively. By observing the effect of material parameters on damage development, composite laminated plates were stacked as two different orientations, [0°/902°/0°]s and [0°/90°]2s. A total of 144 specimens with nine different geometries were tested to obtain the experimental strength and failure mode. Damage progression was examined by using scanning electron microscopy on specimens loaded to ultimate failure and to percentages of their ultimate failure load.
[en] Scanning Electron Microscope FEI-Quanta 400 (SEM) made in the USA was commissioned in late 2003. This equipment is used in many areas of materials science, metallurgy, engineering, electronics, medicine, agriculture, biology and so on. This facility has helped the researchers in conducting research in their respective fields as well have been providing services to agencies, institutions, industries and local industry. Since 2004, there were 81 projects and 5000 samples analyzed using this facility in Malaysian Nuclear Agency, while 23 companies and 900 samples were from various agencies. In addition, revenue derived from these services has able to provide for the maintenance of this equipment. SEM is an important step in the nuclear material testing process. Nuclear material can be inspected for its performance by getting information from its morphology micrograph by using SEM. It opens up a whole new world that is unseen by the naked eye. (author)
[en] A survey is given of applications of high-resolution electron microscopy to elucidate structure-property relations of solids. Examples are presented for imaging lattice fringes, for lattice imaging by multi-beam techniques, for imaging crystal defects, for image processing by computers, and for imaging individual atoms
[en] Pollen morphology of five genera of the family Acanthaceae, namely Ruellia, Blepharis, Asystasia, Ecbolium and Dicliptera (Acanthaceae) of Yemen has been examined using light and scanning electron microscope. Pollen descriptions were provided with two shapes distinguished, spheroidal and prolate. Most of the pollen grains were tricolporate amd psuedocolpi except those of Blepharis which are colpate. The surface is coarsely reticulate, in addition to the lumina that varies in size
[en] The origin of electron channelling patterns (ECPs) is briefly described. A method for generating selected area channelling patterns (SACPs) in a SEM is discussed. A detailed setting-up procedure for obtaining SACPs (down to about 5 um across) on a production SEM, the Cambridge Stereoscan 250 Mk 3, is given. The types of information that can be obtained from SACPs are also discussed
[en] In this study, a more conveniently method was tried to prepare T-shaped groove structure surface with HS-WEDM method on the surface of an aluminum alloy, and the results shown that processed surface has super-hydrophobic and high- adhesion properties. The fabricated surface morphology was observed by scanning electron microscopy and laser confocal and it was found that there are some micrometers or submicron-scale pits and mastoids distributed on the surface of the sample with sub-millimeter T-shaped grooves. This phenomenon can be combined with typical wetting model to explain the reason why the surface of the sample is superhydrophobic. At the same time, by changing the volume, the maximum adhesion that the sample can provide 14 μl of water. Meanwhile, we present a generalized Cassie-Baxter equation to take into account the effect of drop pressure on the apparent contact angle, and determine the limiting pressure pw and the pull-off pressure pout at T-shaped groove structure based on the previous research. (paper)